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Date:   Thu, 22 Jul 2021 02:37:46 +0300
From:   Vladimir Oltean <olteanv@gmail.com>
To:     Lino Sanfilippo <LinoSanfilippo@gmx.de>
Cc:     woojung.huh@microchip.com, UNGLinuxDriver@microchip.com,
        andrew@lunn.ch, vivien.didelot@gmail.com, f.fainelli@gmail.com,
        davem@davemloft.net, kuba@kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 2/2] net: dsa: tag_ksz: dont let the hardware process
 the layer 4 checksum
Message-ID: <20210721233746.qi6tdreubw74l6l2@skbuf>
References: <20210721215642.19866-1-LinoSanfilippo@gmx.de>
 <20210721215642.19866-3-LinoSanfilippo@gmx.de>
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On Wed, Jul 21, 2021 at 11:56:42PM +0200, Lino Sanfilippo wrote:
> If the checksum calculation is offloaded to the network device (e.g due to
> NETIF_F_HW_CSUM inherited from the DSA master device), the calculated
> layer 4 checksum is incorrect. This is since the DSA tag which is placed
> after the layer 4 data is considered as being part of the daa and thus
> errorneously included into the checksum calculation.
> To avoid this, always calculate the layer 4 checksum in software.
> 
> Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
> ---

Fixes: 8b8010fb7876 ("dsa: add support for Microchip KSZ tail tagging")
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>